Tea leaf uniform drying device with multi-layer hot air supply and tea leaf drying method

Abstract

The invention discloses a tea leaf uniform drying device with multi-layer hot air supply and a tea leaf drying method, and belongs to the technical field of tea leaf processing equipment. The device comprises a shell, an air inlet cavity, a driving motor, a plurality of drying discs, an inner barrel, a mounting disc and an exhaust pipe. The drying disc is connected with the inner gear through a connecting shaft and an outer gear, and the edge of the drying disc is provided with a reset spring. A through hole is formed in the outer wall of the inner barrel, an ejector rod is arranged at the top end of the inner barrel, a protruding block on the bottom side of the installation disc is matched with the ejector rod to drive the drying disc to move up and down, and the exhaust pipe communicates with the inner barrel to form hot air supply. According to the drying method, uniform drying is achieved through alternation of cold air and hot air, alternate rotation of the drying disc and up-down displacement overturning. The problems that a traditional device is uneven in hot air distribution and uneven in drying are solved, the heat utilization rate and the drying efficiency are improved, the tea quality is guaranteed, the structure is reasonable, operation is stable, and the device is suitable for large-scale processing.

Description

Technical Field

[0001] This invention relates to the field of drying equipment technology, and in particular to a multi-layer hot air supply uniform tea drying device and a tea drying method. Background Technology

[0002] Tea drying is a crucial step in tea processing. Its uniformity and efficiency directly determine the color, aroma, taste, and quality stability of the tea, thus affecting its commercial value and market competitiveness. With the intelligent and large-scale development of the tea processing industry, traditional tea drying equipment can no longer meet the demands for high-quality and high-efficiency drying, leading to the emergence of various tea drying devices.

[0003] Currently, a uniform heating control device for tea drying (application number: 202411283039.9) already exists in the prior art. This device relates to the field of tea drying technology and includes a drying chamber body. A compressor is installed on the upper surface of the drying chamber body, a controller is installed on the front side of the compressor, a processing rack is installed inside the drying chamber body, uniform drying mechanisms are arranged on the left and right sides of the drying chamber body, and a processing oscillation mechanism is arranged inside the drying chamber body. Its core design concept is to transform the flow mode of compressed air into a high-speed rotating vortex through the structural design of the vortex vane, so that air molecules generate energy separation through friction and collision, thereby increasing their temperature. Combined with the structural position of the subsequent flow divider and vortex tube, it ensures that the hot airflow can directly and efficiently act on each layer of tea raw materials on the processing rack. At the same time, through the structural characteristics of the vortex tube itself, uniform diffusion and vertical penetration of the hot airflow are achieved, attempting to solve the problem of heat attenuation and uneven distribution of the hot airflow during the descent process, so as to improve the uniformity of tea drying.

[0004] However, the aforementioned closest existing technology still has shortcomings in practical applications. Due to the influence of the energy separation efficiency of the vortex tube and the fluctuation of the airflow inlet parameters, the distribution of hot airflow in the multi-layer drying rack is prone to deviation, resulting in over-drying of tea near the inlet and incomplete drying at the far end. Summary of the Invention

[0005] To address the aforementioned deficiencies in existing technologies, the present invention aims to provide a multi-layer hot air supply-based uniform tea drying device and method, specifically addressing the problem of uneven hot air distribution. Uneven hot air distribution in this application refers to the following: when tea leaves are statically piled, the hot airflow can only act on the surface layer of the pile, making it difficult to penetrate the gaps between the leaves and reach the inner layers. The inner layers of tea leaves remain in a closed, humid, and difficult-to-reach state, resulting in significant differences in heat intensity and dehydration rate between the inner and outer layers. This leads to excessively rapid drying of the surface layer and insufficient drying of the inner layer. Furthermore, the overlapping and compression between tea particles create locally dense areas, allowing hot airflow to flow quickly along the less resistant surface path, creating airflow short-circuiting and preventing uniform and effective penetrating heat exchange within the pile. This further exacerbates uneven drying, ultimately resulting in significant differences in moisture content, color, and aroma quality within the same batch of tea.

[0006] (a) A multi-layer hot air supply uniform drying device for tea A multi-layer hot air supply uniform drying device for tea includes a shell and an air inlet chamber. The air inlet chamber is located on the outer side of one side of the shell and communicates with the shell. The multi-layer hot air supply uniform drying device for tea also includes: The drive motor is fixedly mounted on the bottom side of the housing, and the output end is connected to a rotating shaft. The rotating shaft extends into the inside of the housing, and multiple internal gears are fixedly connected to the rotating shaft. Multiple drying trays, each annular in shape, are fitted around the outer side of a corresponding internal gear. A connecting shaft is fixedly installed on the inner side of each drying tray, and an external gear is fixedly connected to the inner end of the connecting shaft. The external gear meshes with the internal gear, allowing the drying tray to engage and drive through the connecting shaft, the external gear, and the internal gear. Annular sliding plates are provided on the top and bottom sides of the edge of each drying tray, with the drying tray held between two annular sliding plates and able to rotate circumferentially relative to them. Multiple return springs are provided on the outer side of each annular sliding plate, with one end fixedly connected to the annular sliding plate and the other end fixedly connected to the housing via a fixing ring. This allows the drying tray to move axially up and down along with the annular sliding plate under the action of the return springs, while maintaining circumferential rotation capability. The inner cylinder is made of a high thermal conductivity metal material and has a ring-shaped cross-section. It is sleeved on the outside of the internal gear and fixedly connected to the connecting shaft. It is used to rotate the inner cylinder and the drying tray synchronously. There are through holes evenly arranged on the outer wall of the inner cylinder, and N top rods are evenly arranged at the top of the inner cylinder, where N ≥ 3. The mounting plate is fixedly installed inside the housing and located on the top side of the inner cylinder. It is fixedly connected to the housing. N arc-shaped protrusions are fixedly installed on the bottom side of the mounting plate. The N protrusions and N push rods are arranged alternately and coaxially. When the drying tray rotates, the protrusions drive the inner cylinder and the push rods to rotate in sequence. When the protrusions contact the push rods, they push the push rods and drive the inner cylinder and the drying tray to move downward along the axial direction. When the push rods pass the protrusions, the elastic return springs drive the inner cylinder and the drying tray to return to their original position upward. The exhaust pipe is located on the top side of the casing and connects to the inner cylinder.

[0007] Furthermore, the outer diameter of the inner cylinder is less than 1 / 6 of the diameter of the drying tray. This size design ensures that a sufficiently voluminous annular cavity is formed between the inner cylinder and the outer shell, while ensuring that the through holes on the outer wall of the inner cylinder can evenly discharge the supplied hot air, avoiding the problem of the inner cylinder occupying cavity space due to being too large, or the hot air supply being poor due to being too small.

[0008] Furthermore, it also includes vibration damping springs, which are located inside the housing and on top of the drive motor, with both ends connected to the housing and the drying tray, respectively. The vibration damping springs effectively buffer the impact force generated when the drying tray moves up and down, preventing excessive vertical displacement from disrupting the stability of the hot air supply, while also reducing noise during operation and extending the service life of each component.

[0009] Furthermore, the air intake chamber includes two chambers, symmetrically arranged on both sides of the shell. The two air intake chambers can serve as hot air chambers and cold air chambers respectively, realizing separate supply and precise control of hot and cold air. Combined with the annular chamber and the flow guiding structure, it ensures that the hot and cold airflows are evenly diffused to each drying tray, providing a stable airflow basis for the alternating drying of tea leaves.

[0010] Furthermore, it also includes a top guide plate and multiple bottom guide plates. Each top and bottom guide plate has a funnel-shaped structure and is fitted onto the outside of the inner cylinder. The inner side of the top guide plate is fixed to the inner cylinder, while the outer side is slidably connected to the inner wall of the shell. Each bottom guide plate is fixed to the bottom side of the drying tray. The funnel-shaped guide plates can precisely guide the airflow entering the air inlet cavity, avoiding local airflow concentration and ensuring that the airflow flows evenly to each drying tray.

[0011] Furthermore, the bottom of the shell is designed in a conical shape, with a drain pipe on the outer side of the shell. The drain pipe is connected to the inner side of the shell, and its inner end face is located on the top side of the bottom surface of the shell. The conical bottom allows the condensate generated during the drying process to naturally collect along the inner wall of the shell to the bottom, and then be discharged in time through the drain pipe. This prevents the condensate from flowing back onto the surface of the tea leaves, thus preventing mold growth and improving the drying quality and product qualification rate.

[0012] Furthermore, multiple concentric annular partitions are fixed to the top side of the drying tray, with each partition perpendicularly connected to the tray. A horizontal partition is positioned above the concentric partitions, with a gap between it and the concentric partitions. The outer edge of the horizontal partition is fixedly connected to the inner wall of the casing. Multiple hinged brackets are located on the bottom side of the horizontal partitions, with a connecting rod hinged to the bottom of each bracket. The connecting rod is positioned between two adjacent concentric partitions, at an angle, and in contact with the drying tray. The concentric partitions divide the drying tray into multiple annular areas, preventing excessive accumulation of tea leaves during tray rotation. The connecting rod swings with the vertical movement of the drying tray, allowing for omnidirectional turning of the tea leaves, ensuring that each leaf is fully in contact with the hot airflow and further improving drying uniformity.

[0013] (ii) A method for drying tea leaves A method for drying tea leaves, applied to any of the above-mentioned multi-layer hot air supply uniform tea drying devices, the method comprising the following steps: S1. Feeding Preparation: Evenly spread the tea leaves to be dried on multiple drying trays of the drying device, ensuring a consistent thickness between adjacent concentric partitions, and preventing the tea leaves from covering the connecting shafts, external gears, hinged supports, and linkage structures on the drying trays. The tea leaf thickness should be controlled between 2-5cm. This thickness ensures that the hot airflow can penetrate the tea leaves while avoiding incomplete drying due to excessive thickness. It also prevents the tea leaves from covering the connecting shafts, external gears, hinged supports, and linkage structures, thus avoiding interference with the rotation, vertical movement, and airflow of the drying trays.

[0014] S2. Hot and Cold Air Supply and Hot Air Supply Formation: The two symmetrical air inlet chambers of the drying device serve as the hot air chamber and the cold air chamber, respectively. First, the hot air chamber is activated to introduce hot air into the shell. After being guided by the top and bottom guide plates, the hot air flow is evenly diffused to each drying tray along the annular cavity between the shell and the inner cylinder, making full contact with the tea leaves for heat exchange. Then, it enters the inner cylinder through the through holes on the outer wall of the inner cylinder and is discharged through the exhaust pipe. After the hot air supply is completed, the hot air chamber is closed, and then the cold air chamber is activated to introduce cold air. The cold air flow follows the same path as the hot air flow, realizing the time-sharing alternating supply of hot and cold air.

[0015] The hot air temperature in the hot air chamber is controlled at 60-85℃, and the wind speed is controlled at 1.2-2.0 m / s; the cold air temperature in the cold air chamber is controlled at 15-25℃, and the wind speed is consistent with the hot air speed; the airflow rate in both air inlet chambers is consistent. This parameter setting enables alternating hot and cold drying, avoiding damage to the color and aroma of tea leaves caused by continuous high-temperature drying. At the same time, the hot airflow is guided by the guide plate and flows evenly along the annular cavity through each drying tray, and enters the inner cylinder through the through holes, improving heat utilization efficiency.

[0016] S3. Alternating Rotation Drying and Jumping Turning: Start the drive motor, set the intermittent rotation time of the rotating shaft, and control the rotating shaft to drive multiple internal gears, drying trays and inner cylinder to rotate synchronously; after the preset rotation time, stop rotating, and at this time turn on the hot air supply so that the tea on the drying tray is dried by hot air in a static state; after the hot air drying is completed, turn off the hot air and turn on the cold air supply, and at the same time restart the rotating shaft to continue rotating, so that the tea is dried by cold air in a rotating state, thereby realizing the alternating mode of cold air drying and hot air drying; When the push rod contacts the protrusion on the bottom side of the mounting plate, the protrusion exerts a squeezing force on the push rod, causing the inner cylinder and drying plate to move downward along the axial direction. After the push rod passes the protrusion, it moves the drying plate back upward along the axial direction under the elastic reset action of the return spring, thus forming a periodic axial up-and-down displacement. During the axial up-and-down displacement, the connecting rod on the bottom side of the horizontal partition, in conjunction with the reciprocating motion of the drying plate, turns and disperses the tea leaves, preventing local accumulation of tea leaves.

[0017] The rotating shaft alternates between rotation and stop times of 10-15 minutes, and the drying trays rotate at a speed of 10-20 rpm, with multiple trays rotating synchronously in the same direction. During rotation, damping springs buffer the vertical displacement of the drying trays, controlling the displacement to 0.5-1.5 cm. This setup ensures the tea leaves are heated evenly during rotation, while the vertical displacement prevents the tea leaves from adhering to the drying tray surface, ensuring each leaf is fully in contact with the hot airflow.

[0018] S4. Moisture and Condensate Removal: During the drying process, the moisture generated by the tea leaves enters the inner cylinder with the supplied airflow and is then discharged outside the shell through the exhaust pipe on the top side of the shell. The condensate generated collects along the conical bottom side of the shell and is discharged through the drain pipe. Timely removal of moisture prevents excessive moisture in the hot air supply from affecting drying efficiency, and timely removal of condensate prevents it from flowing back to the surface of the tea leaves, ensuring drying quality.

[0019] S5. Drying Completed: Continue executing steps S2-S4, maintaining the alternating hot and cold drying mode, until the tea leaves are dried to the preset moisture content. Then, turn off the drive motor and the two air intake chambers to complete the tea drying process. The preset moisture content of the tea leaves is 5%-8%, which ensures stable tea quality, prevents mold growth, and preserves the original color and aroma of the tea.

[0020] Compared with the prior art, the present invention has the following beneficial effects: To address the problem of uneven hot airflow distribution: This invention abandons the existing method of relying on vortex tubes and swirl vanes for airflow diffusion, instead employing two symmetrically arranged air inlet chambers to replace a single air inlet structure. This results in a more stable and uniform airflow supply, unaffected by fluctuations in inlet pressure and flow rate. Simultaneously, this invention constructs a hot air supply and moisture exhaust channel consisting of "air inlet chamber → annular cavity between the shell and inner cylinder → multi-layer drying trays → through holes on the outer wall of the inner cylinder → inside the inner cylinder → exhaust pipe." Combined with the guiding effect of the top and bottom guide plates, this prevents localized concentration of hot airflow, completely resolving the problem of uneven hot airflow distribution.

[0021] Improving drying uniformity and tea quality: The drive motor drives the rotating shaft, internal gear, and multi-layer drying trays to rotate synchronously and intermittently. In conjunction with the contact and compression between the inner cylinder top rod and the mounting plate protrusion, the drying trays are moved up and down under the action of the return spring. At the same time, the connecting rod on the bottom side of the horizontal partition moves up and down with the drying trays to turn the tea leaves, preventing them from adhering and piling up. This ensures that each tea leaf can fully contact the hot airflow, guaranteeing that the moisture content of the multi-layer tea leaves is consistent and improving the consistency of tea quality.

[0022] Reduced energy consumption and improved heat utilization: After the hot airflow completes the heating and drying of the tea leaves, it carries the moisture into the inner cylinder made of a highly thermally conductive metal material. Before being discharged through the exhaust pipe, the hot and humid air carrying residual heat flows through the inside of the inner cylinder, efficiently transferring its residual heat to the inner cylinder wall through convection heat transfer, causing the cylinder to heat up rapidly and maintain a high temperature, thus achieving preheating and heat preservation of the inner cylinder.

[0023] The heated inner cylinder then uses heat conduction and radiation to transfer the recovered waste heat back to the drying area, providing secondary heating for the tea leaves and the drying environment. This fully utilizes the waste heat before exhaust, preventing direct heat loss to the outside. Compared to existing technologies where hot air is directly discharged and waste heat is not utilized, this design significantly improves heat utilization and effectively reduces energy consumption. Simultaneously, damping springs buffer the vertical movement of the drying trays, ensuring stable hot air supply and further enhancing drying efficiency.

[0024] To avoid the impact of condensation and improve product qualification rate: The bottom of the shell is designed with a conical structure, which, together with the drain pipe, can promptly drain the condensation generated during the drying process, preventing the condensation from flowing back to the surface of the tea leaves, thus preventing the tea leaves from becoming moldy and improving the product qualification rate. This makes up for the shortcomings of existing technologies that have not specifically addressed the condensation problem.

[0025] Reasonable structure and strong practicality: The components of this invention are compactly connected, and the drying tray, guide plate, connecting rod and other components can be easily disassembled and maintained. It is also highly intelligent, requiring no frequent manual adjustment, and is suitable for drying different types of tea with different laying thicknesses, making it easy to promote and apply. Attached Figure Description

[0026] Other features and advantages of the invention will become clear from the following description of exemplary embodiments, which is incorporated in and constitutes a part of this specification. The accompanying drawings, which illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In these drawings, similar reference numerals are used to denote similar elements. The drawings described below are some embodiments of the invention, but not all embodiments. Other drawings will be readily available to those skilled in the art based on these drawings without any inventive effort.

[0027] In the picture: Figure 1 A schematic diagram of the structure of the multi-layer hot air supply uniform tea drying device of the present invention; Figure 2 A schematic diagram of the internal structure of the multi-layer hot air supply uniform tea drying device of the present invention. Figure 3 A schematic diagram of the top rod without a fixed pressure protrusion in the multi-layer hot air supply uniform tea drying device of the present invention. Figure 4 A schematic diagram of the pressure-regulating protrusion on the top rod of the multi-layer hot air supply uniform tea drying device of the present invention. Figure 5 This invention provides a multi-layer hot air supply for uniformly drying tea leaves. Figure 2 Enlarged view of position A; Figure 6 A schematic diagram of the drying tray structure of the multi-layer hot air supply uniform tea drying device of the present invention. Figure 7 A schematic diagram of the mounting plate structure of the multi-layer hot air supply uniform tea drying device of the present invention. Figure 8 An enlarged schematic diagram of the reset spring part of the multi-layer hot air supply uniform tea drying device of the present invention.

[0028] 100. Housing; 101. Air intake chamber; 10. Drive motor; 11. Rotating shaft; 12. Internal gear; 20. Drying tray; 21. Connecting shaft; 22. External gear; 23. Return spring; 24. Fixing ring; 30. Inner cylinder; 31. Through hole; 32. Top rod; 40. Mounting plate; 41. Protrusion; 102. Exhaust pipe; 25. Vibration damping spring; 50. Top guide plate; 51. Bottom guide plate; 103. Drain pipe; 60. Concentric partition; 61. Horizontal partition; 62. Hinge bracket; 63. Connecting rod; 200. Annular sliding plate. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0030] The following description, in conjunction with the accompanying drawings and embodiments, details the multi-layer hot air supply uniform tea drying device.

[0031] Example 1 This embodiment provides a basic multi-layer hot air supply uniform tea drying device, ensuring the realization of the core hot air supply path and the vertical displacement and turning function.

[0032] The multi-layer hot air supply uniform tea drying device includes a shell 100, an air inlet chamber 101, a drive motor 10, a drying tray 20, an inner cylinder 30, a mounting plate 40, and an exhaust pipe 102.

[0033] The air intake chamber 101 is located on the outside of the housing 100 and is connected to the housing 100, and is used to supply airflow into the housing 100.

[0034] The drive motor 10 is fixedly mounted on the bottom side of the housing 100, and its output end is connected to a rotating shaft 11, which extends into the inside of the housing 100. Multiple internal gears 12 are connected to the rotating shaft 11.

[0035] The drying tray 20 has a ring-shaped structure and is fitted around the outer side of the internal gear 12. Each drying tray 20 is ring-shaped and fitted around the outer side of the corresponding internal gear 12. A connecting shaft 21 is fixedly installed on the inner side of each drying tray 20, and an external gear 22 is fixedly connected to the inner end of the connecting shaft 21. The external gear 22 meshes with the internal gear 12, so that the drying tray 20 forms a meshing transmission with the internal gear 12 through the connecting shaft 21, the external gear 22 and the internal gear 12. Annular sliding plates 200 are respectively provided on the top and bottom sides of the edge of the drying tray 20. The drying tray 20 is clamped between two annular sliding plates 200 and can rotate circumferentially relative to the annular sliding plates 200. Multiple return springs 23 are provided on the outer side of each annular sliding plate 200. One end of the return spring 23 is fixedly connected to the annular sliding plate 200, and the other end is fixedly connected to the housing 100 through a fixing ring 24, so that the drying tray 20 can move up and down axially along with the annular sliding plate 200 under the action of the return spring 23, while maintaining circumferential rotation capability.

[0036] The inner cylinder 30 has an annular cross-section and is made of a highly thermally conductive metal material, and is fitted onto the outside of the internal gear 12. The inner cylinder 30 is fixedly connected to the connecting shaft 21, so the inner cylinder 30 can rotate synchronously with the drying tray 20. The outer wall of the inner cylinder 30 is uniformly provided with through holes 31 through which hot air flows; N top rods 32 are evenly spaced at its top, where N≥3, and in this embodiment, 6 are preferred.

[0037] The mounting plate 40 is fixedly disposed inside the housing 100 and located on the top side of the inner cylinder 30, and is fixedly connected to the housing 100. N arc-shaped protrusions 41 are fixedly disposed on the bottom side of the mounting plate 40. In this embodiment, six protrusions are preferred. The protrusions 41 and the push rod 32 are arranged alternately, and both are located on the same circumference. When the drying tray 20 rotates, the push rod 32 rotates with the inner cylinder 30, such that when the protrusion 41 contacts the push rod 32, it pushes the push rod 32, causing the inner cylinder 30 and the drying tray 20 to move downwards axially; when the push rod 32 passes the protrusion 41, it moves the inner cylinder 30 and the drying tray 20 back to their original position under the elastic reset action of the return spring 23.

[0038] The exhaust pipe 102 is located on the top side of the housing 100 and is connected to the interior of the inner cylinder 30 to discharge moisture from the supplied airflow.

[0039] Working principle Airflow enters through the inlet chamber 101, flows through the annular cavity between the shell 100 and the inner cylinder 30, surrounds the multi-layer drying trays 20, and exchanges heat with the tea leaves on the trays. Subsequently, the airflow enters the interior of the inner cylinder 30 through the through hole 31 on the outer wall of the inner cylinder 30, and finally exits through the exhaust pipe 102. During the rotation of the drying trays 20, when the protrusion 41 contacts the push rod 32, the push rod 32 pushes the inner cylinder 30 and the drying trays 20 to move downward along the axial direction. After the push rod 32 passes the protrusion 41, under the elastic reset action of the return spring 23, it drives the inner cylinder 30 and the drying trays 20 to return to their original position, realizing automatic turning of the tea leaves, avoiding tea leaf accumulation, and ensuring uniform drying.

[0040] It should be noted that, regarding the problem that vertical displacement of the drying tray 20 may lead to unstable meshing, increased wear, or even jamming between the internal gear 12 and the external gear 22, this application achieves axial limiting and buffering through a return spring 23 located at the edge of the drying tray 20. The return spring 23 provides a stable axial preload to the drying tray 20, limiting the vertical displacement of the drying tray 20, ensuring that the external gear 22 and the internal gear 12 are always kept within a safe meshing range, avoiding disengagement or tooth clipping, ensuring smooth transmission, reducing gear wear, and preventing jamming. Simultaneously, the internal gear 12 and the external gear 22 adopt a wide tooth width structure, with the tooth width dimension greater than the vertical displacement stroke of the drying tray 20, ensuring that the external gear 22 and the internal gear 12 are always stably meshed within the vertical displacement range, without disengagement or jamming.

[0041] In this embodiment, the outer diameter of the cross-section of the inner cylinder 30 is less than 1 / 6 of the diameter of the drying tray 20. This size design ensures that a sufficiently voluminous annular cavity is formed between the inner cylinder 30 and the shell 100, while ensuring that the through holes 31 on the outer wall of the inner cylinder 30 can uniformly discharge the supplied hot air, avoiding the problem of the inner cylinder 30 occupying cavity space due to being too large, or the hot air supply being unsmooth due to being too small.

[0042] To further optimize the stability of the device operation, this embodiment also provides a vibration damping spring 25 inside the housing 100 and on the top side of the drive motor 10. The two ends of the vibration damping spring 25 are connected to the housing 100 and the bottom drying tray 20, respectively. It can effectively buffer the vibration generated during the vertical movement of the drying tray 20, reduce noise, protect the drive motor 10 and its connecting components, and extend the service life of the equipment.

[0043] Example 2 Based on Example 1, this embodiment optimizes the air intake layout, airflow guiding structure, and bottom side design of the housing to improve the uniformity of airflow distribution and the practicality of the equipment.

[0044] Dual air intake chamber layout: In this embodiment, there are two air intake chambers 101, which are symmetrically arranged on both sides of the housing 100. This symmetrical design allows the airflow entering from both sides to fill the annular chambers on both sides more evenly, avoiding uneven airflow distribution that may be caused by single-sided air intake, and ensuring that the tea leaves on the multi-layer drying trays 20 can receive uniform hot air blowing.

[0045] Airflow guide structure: This embodiment adds a top airflow guide 50 and multiple bottom airflow guides 51. Both the top airflow guide 50 and the bottom airflow guides 51 are funnel-shaped and are fitted onto the outside of the inner cylinder 30. The inner side of the top airflow guide 50 is fixed to the inner cylinder 30, and the outer side is slidably connected to the inner wall of the shell 100. The bottom airflow guides 51 are fixed to the bottom side of the drying tray 20. These funnel-shaped airflow guides can effectively guide the airflow, allowing the airflow from the air inlet cavity 101 to flow more smoothly and concentratedly to the tea area of ​​each drying tray 20, eliminating dead airflow corners and further improving drying uniformity.

[0046] Conical bottom and drain pipe: The bottom of the shell 100 is designed in a conical shape, which facilitates the collection of condensate generated during the drying process. A drain pipe 103 is provided on the outside of the shell 100, connecting to the inside of the shell 100, with its inner end face located on the top side of the bottom surface of the shell 100. Condensate collects along the conical inner wall to the bottom and can be discharged promptly through the drain pipe 103, preventing water accumulation, maintaining a dry drying environment, and avoiding mold growth on the tea leaves due to contact with water.

[0047] Example 3 Based on Embodiment 1 or 2, this embodiment uses a concentric partition and linkage mechanism to enhance the turning effect, ensuring that the tea leaves are turned over evenly and comprehensively during the drying process.

[0048] On the top side of the drying tray 20, multiple concentric annular partitions 60 are fixedly installed. Each concentric partition 60 is vertically connected to the drying tray 20, and they divide the annular area of ​​the drying tray 20 into multiple concentric, independent tea-holding areas to prevent the tea leaves from all flowing to the edge of the drying tray under the action of centrifugal force.

[0049] A horizontal partition 61 is provided above the concentric partition 60, with a gap between the horizontal partition 61 and the concentric partition 60, and the outer edge of the horizontal partition 61 is fixedly connected to the inner wall of the housing 100; multiple hinged brackets 62 are provided on the bottom side of the horizontal partition 61, and a connecting rod 63 is hinged to the bottom side of each hinged bracket 62. The connecting rod 63 is located between two adjacent concentric partitions 60, in an inclined state, and its bottom end is in contact with the surface of the drying tray 20.

[0050] Workflow When the drying tray 20 moves up and down under the action of the return spring 23, the bottom end of the connecting rod 63 swings along with the up-and-down movement of the drying tray 20. This swinging action acts on the tea leaves in adjacent concentric areas, on the one hand, dispersing the accumulated tea leaves and distributing them evenly within the annular area; on the other hand, breaking the adhesion between the tea leaves and the surface of the drying tray 20, allowing the surface of the tea leaves to be exposed to the hot airflow. Combined with the rotation of the drying tray 20, this achieves three-dimensional tumbling of the tea leaves, ensuring that each tea leaf is heated evenly, achieving an excellent drying effect.

[0051] Example 4 This embodiment, based on the limitations of claim 8, provides a complete basic method and process for drying tea using the aforementioned drying device.

[0052] Drying method steps S1. Feeding Preparation: Open the inspection door of the housing 100 and evenly spread the tea leaves to be dried on multiple drying trays 20, controlling the thickness of the tea leaves to be 2-5cm. During spreading, ensure that the thickness of the tea leaves between adjacent concentric partitions 60 is consistent, and ensure that the tea leaves do not cover the connecting shaft 21, external gear 22, hinged bracket 62, and connecting rod 63 structures on the drying tray 20, so as not to affect rotation and airflow supply. After spreading, close the inspection door and check that all components are securely connected.

[0053] S2. Hot and cold air supply and hot air supply formation: The two symmetrical air inlet chambers 101 of the drying device serve as the hot air chamber and the cold air chamber, respectively. First, the hot air chamber is activated to introduce hot air into the shell 100. After the hot air flow is guided by the top guide plate 50 and the bottom guide plate 51, it is evenly diffused to each drying tray 20 along the annular cavity between the shell 100 and the inner cylinder 30, and fully contacts the tea leaves for heat exchange. Then, it enters the inner cylinder 30 through the through hole 31 on the outer wall of the inner cylinder 30 and is discharged through the exhaust pipe 102. After the hot air supply is completed, the hot air chamber is closed, and then the cold air chamber is activated to introduce cold air. The cold air flow follows the same path as the hot air flow, realizing the time-sharing alternating supply of hot and cold air.

[0054] S3. Alternating rotation drying and jumping turning: Start the drive motor 10, set the intermittent rotation time of the rotating shaft 11, and control the rotating shaft 11 to drive multiple internal gears 12, drying trays 20 and inner cylinder 30 to rotate synchronously; after the preset rotation time, stop the rotation, and at this time turn on the hot air supply so that the tea leaves on the drying trays 20 are dried by the hot air in a static state; after the hot air drying is completed, turn off the hot air and turn on the cold air supply, and at the same time restart the rotating shaft 11 to continue rotating so that the tea leaves are dried by the cold air in a rotating state, thereby realizing the alternating mode of cold air drying and hot air drying; During the rotation of the drying tray 20, the top rod 32 at the top of the inner cylinder 30 rotates with it. When the top rod 32 contacts the protrusion 41 on the bottom side of the mounting plate 40, the protrusion 41 exerts a squeezing force on the top rod 32, causing the inner cylinder 30 and the drying tray 20 to move downward along the axial direction. After the top rod 32 passes the protrusion 41, it is driven to return to its original position axially under the elastic reset action of the return spring 23, thus forming a periodic axial up-and-down displacement. During the axial up-and-down displacement, the connecting rod 63 on the bottom side of the horizontal partition 61, in conjunction with the up-and-down reciprocating motion of the drying tray 20, turns and disperses the tea leaves, preventing local accumulation of tea leaves.

[0055] S4. Moisture and Condensate Discharge: During the drying process, the moisture released by the tea leaves enters the inner cylinder 30 with the supplied airflow and is discharged outside the shell 100 through the exhaust pipe 102 on the top side of the shell 100. At the same time, the water vapor in the airflow condenses upon cooling to form condensate, which drips along the guide plate to the circumference of the connecting shaft 21 and converges along the conical bottom side of the shell 100, and is discharged outside the device through the drain pipe 103.

[0056] S5. Drying complete: Continue executing steps S2 to S4, maintaining the alternating hot and cold drying mode until the moisture content of the tea leaves reaches the preset standard. Once the standard is reached, turn off the drive motor 10 and the two air intake chambers 101 to complete the entire tea drying process.

[0057] Example 5 Based on the limitations of claims 9-10, this embodiment further specifies the key process parameters in the drying method in accordance with the limitations of embodiment four, so as to obtain a stable and high-quality dried product.

[0058] Airflow parameters: In step S2, the temperature of the hot air introduced into the hot air chamber is strictly controlled between 60-85℃, and the wind speed is controlled between 1.2-2.0 m / s. The temperature of the cold air introduced into the cold air chamber is controlled between 15-25℃, and its wind speed is consistent with that of the hot air. The airflow rates introduced into the two air inlet chambers 101 are kept the same to ensure a balanced and stable airflow supply. This combination of parameters can effectively stimulate the transformation of effective substances in tea leaves while avoiding damage to the tea leaves due to excessively high temperatures.

[0059] process parameters Feed thickness: In step S1, the thickness of the tea leaves is controlled within the range of 2-5cm. This thickness range ensures that there is enough tea leaves to be loaded, and also ensures that the hot airflow can penetrate the tea leaf layer smoothly, thus ensuring the drying effect of the tea leaves inside.

[0060] Rotation and vibration parameters: In step S3, the rotation time and stop time of the rotating shaft 11 are set to alternate between 10-15 minutes. The rotation speed of the drying trays 20 is controlled at 10-20 r / min, and all drying trays 20 rotate synchronously in the same direction. During the vertical displacement of the drying trays 20, the vertical displacement amplitude is buffered by the damping springs 25, controlling the vertical displacement amplitude of the drying trays 20 to 0.5-1.5 cm. Reasonable rotation speed and vertical displacement amplitude ensure a balance between the material turning effect and the stability of equipment operation.

[0061] Moisture content target: In step S5, the preset moisture content of the tea leaves is set to 5%-8%. This is the ideal range for drying and storing tea leaves, which can ensure that the tea leaves are dry and not prone to mold, while also preserving the aroma and nutrients of the tea leaves to the greatest extent.

Claims

1. A multi-layer hot air supply uniform tea drying device, comprising a housing (100) and an air inlet chamber (101), wherein the air inlet chamber (101) is disposed outside the housing (100) and communicates with the housing (100), characterized in that, The multi-layer hot air supply tea drying device also includes: A drive motor (10) is fixedly installed on the bottom side of the housing (100), and a rotating shaft (11) is connected to the output end. The rotating shaft (11) extends into the inside of the housing (100), and multiple internal gears (12) are connected to the rotating shaft (11). Multiple drying trays (20), each of the drying trays (20) being annular and sleeved on the outside of the corresponding internal gear (12); a connecting shaft (21) is fixedly provided on the inner side of each drying tray (20), and an external gear (22) is fixedly connected to the inner end of the connecting shaft (21), the external gear (22) meshing with the internal gear (12). The drying tray (20) is connected to the internal gear (12) via the connecting shaft (21), the external gear (22), and the internal gear (12). Annular sliding plates (200) are provided on the top and bottom sides of the edge of the drying tray (20). The drying tray (20) is held between the two annular sliding plates (200) and can rotate circumferentially relative to the annular sliding plates (200). Multiple return springs (23) are provided on the outer side of each annular sliding plate (200). One end of the return spring (23) is fixedly connected to the annular sliding plate (200), and the other end is fixedly connected to the housing (100) via a fixing ring (24). This allows the drying tray (20) to move axially up and down along with the annular sliding plate (200) under the action of the return spring (23), while maintaining circumferential rotation capability. The inner cylinder (30) is made of a high thermal conductivity metal material and has a ring-shaped cross-section. It is sleeved on the outside of the inner gear (12) and fixedly connected to the connecting shaft (21) to make the inner cylinder (30) rotate synchronously with the drying tray (20). Through holes (31) are uniformly arranged on the outer wall of the inner cylinder (30), and N top rods (32) are evenly arranged at the top of the inner cylinder (30), where N ≥ 3. The mounting plate (40) is fixedly disposed inside the housing (100) and located on the top side of the inner cylinder (30), and is fixedly connected to the housing (100). N arc-shaped protrusions (41) are fixedly disposed on the bottom side of the mounting plate (40). The N protrusions (41) and N top rods (32) are arranged alternately, and the N protrusions (41) and N top rods (32) are arranged on the same circumference. The protrusions (41) are used when the drying tray ( 20) When rotating, the inner cylinder (30) and the top rod (32) are rotated in sequence, so that when the protrusion (41) contacts the top rod (32), the top rod (32) pushes the inner cylinder (30) and the drying tray (20) to move downward along the axial direction; when the top rod (32) passes the protrusion (41), the inner cylinder (30) and the drying tray (20) are moved upward under the elastic reset action of the return spring (23); An exhaust pipe (102) is provided on the top side of the housing (100) and communicates with the inner cylinder (30); The multi-layer hot air supply uniform drying device for tea forms an annular cavity between the air inlet cavity (101), the shell (100) and the inner cylinder (30), and a hot air supply channel from the drying tray (20), the through hole (31) of the inner cylinder (30) to the exhaust pipe (102).

2. The multi-layer hot air supply uniform tea drying device according to claim 1, characterized in that, The outer diameter of the cross-section of the inner cylinder (30) is less than 1 / 6 of the diameter of the drying tray (20).

3. The multi-layer hot air supply uniform tea drying device according to claim 1, characterized in that, The multi-layer hot air supply uniform drying device for tea also includes a damping spring (25), which is located inside the housing (100) and on the top side of the drive motor (10), with its two ends connected to the housing (100) and the bottom drying tray (20) respectively.

4. The multi-layer hot air supply uniform tea drying device according to claim 1, characterized in that, The air intake chamber (101) includes two chambers, which are symmetrically arranged on both sides of the housing (100).

5. The multi-layer hot air supply uniform tea drying device according to claim 3, characterized in that, It also includes a top guide plate (50) and multiple bottom guide plates (51). Each of the top guide plates (50) and the bottom guide plates (51) is funnel-shaped and is sleeved on the outside of the inner cylinder (30). The inner side of the top guide plate (50) is fixed on the inner cylinder (30), and the outer side is slidably connected to the inner wall of the shell (100). Each of the bottom guide plates (51) is fixed on the bottom side of the drying tray (20).

6. The multi-layer hot air supply uniform tea drying device according to claim 5, characterized in that, The bottom side of the housing (100) is provided with a conical structure, and a drain pipe (103) is provided on the outside of the housing (100). The drain pipe (103) is connected to the inside of the housing (100), and its inner end face is provided on the top side of the bottom surface of the housing (100).

7. The multi-layer hot air supply uniform tea drying device according to claim 6, characterized in that, The top side of the drying tray (20) is also fixed with a plurality of concentric annular partitions (60), and any one of the concentric partitions (60) is perpendicularly connected to the drying tray (20); A horizontal partition (61) is provided above the concentric partition (60), and there is a gap between the horizontal partition (61) and the concentric partition (60). The outer edge of the horizontal partition (61) is fixedly connected to the inner wall of the housing (100). A plurality of hinged brackets (62) are provided on the bottom side of the horizontal partition (61). A connecting rod (63) is hinged on the bottom side of any of the hinged brackets (62). The connecting rod (63) is arranged between two adjacent concentric partitions (60), and is inclined and in contact with the drying tray (20).

8. A method for drying tea leaves, applied to the multi-layer hot air supply uniform tea drying device as described in claim 7, characterized in that, The method includes the following steps: S1. Feeding preparation: The tea leaves to be dried are evenly spread on multiple drying trays (20) of the drying device, and the thickness of the tea leaves between adjacent concentric partitions (60) is controlled to be consistent, and the tea leaves do not cover the connecting shaft (21), external gear (22), hinge bracket (62) and connecting rod (63) structure on the drying tray (20); S2. Hot and cold air supply and hot air supply formation: The two symmetrical air inlet chambers (101) of the drying device serve as the hot air chamber and the cold air chamber, respectively. First, the hot air chamber is activated to introduce hot air into the shell (100). After the hot air flow is guided by the top guide plate (50) and the bottom guide plate (51), it is evenly diffused along the annular cavity between the shell (100) and the inner cylinder (30) to each drying tray (20), fully contacting and exchanging heat with the tea leaves. Then, it enters the inner cylinder (30) through the through hole (31) on the outer wall of the inner cylinder (30) and is discharged through the exhaust pipe (102). After the hot air supply is completed, the hot air chamber is closed, and then the cold air chamber is activated to introduce cold air. The cold air flow follows the same path as the hot air flow, realizing the time-sharing alternating supply of hot and cold air. S3. Alternating Rotation Drying and Jumping Turning: Start the drive motor (10), set the intermittent rotation time of the rotating shaft (11), and control the rotating shaft (11) to drive multiple internal gears (12), drying tray (20) and inner cylinder (30) to rotate synchronously; after the preset rotation time, stop rotating, and at this time turn on the hot air supply so that the tea on the drying tray (20) is dried by hot air in a static state; after the hot air drying is completed, turn off the hot air, turn on the cold air supply, and at the same time restart the rotating shaft (11) to continue rotating so that the tea is dried by cold air in a rotating state, thereby realizing the alternating mode of cold air drying and hot air drying; When the push rod (32) contacts the protrusion (41) on the bottom side of the mounting plate (40), the protrusion (41) exerts a squeezing force on the push rod (32), causing the inner cylinder (30) and the drying plate (20) to move downward along the axial direction. After the push rod (32) passes the protrusion (41), it is driven to return to the axial position by the elastic reset action of the return spring (23), thus forming a periodic axial up and down displacement. During the axial up and down displacement, the connecting rod (63) on the bottom side of the horizontal partition (61) cooperates with the up and down reciprocating motion of the drying plate (20) to turn and disperse the tea leaves, avoiding local accumulation of tea leaves. S4. Moisture and condensate discharge: Moisture generated during the drying process enters the inner cylinder (30) with the supply airflow, and is then discharged outside the shell (100) through the exhaust pipe (102) on the top side of the shell (100). The condensate generated gathers along the conical bottom side of the shell (100) and is discharged through the drain pipe (103). S5. Drying complete: Continue to execute steps S2-S4, maintain the alternating hot and cold drying mode until the tea leaves are dried to the preset moisture content, turn off the drive motor (10) and the two air inlet chambers (101) to complete the drying of the tea leaves; wherein, the hot air temperature is 60-85℃ and the cold air temperature is 15-25℃.

9. The tea drying method according to claim 8, characterized in that, In step S2, the hot air velocity introduced into the hot air chamber is controlled at 1.2-2.0 m / s; The air velocity introduced into the cold air cavity is the same as the hot air velocity; The airflow rates introduced into the two air intake chambers (101) are kept consistent; After being guided by the guide plate, the hot airflow flows evenly along the annular cavity through each drying tray (20) and enters the inner cylinder (30) through the through hole (31).

10. The tea drying method according to claim 8, characterized in that, In step S1, the thickness of the tea leaves should be controlled between 2-5cm. In step S3, the rotation time and stop time of the rotating shaft (11) are set to alternate between 10-15 min; the rotation speed of the drying tray (20) is controlled at 10-20 r / min, and multiple drying trays (20) rotate synchronously in the same direction; during the rotation, the vertical displacement amplitude of the drying tray (20) is buffered by the damping spring (25), and the vertical displacement amplitude is controlled at 0.5-1.5 cm; In step S5, the preset moisture content of the tea leaves is 5%-8%.

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